At the present time, the broad problem of purifying water and particularly desalinating water is meeting with a large amount of attention from engineers, inventors and research workers. Thus it is known to introduce air and water vapor under pressure into a mixing chamber and to circulate the mixture of air and vapor through a system including a condenser and in which some of the air is recovered from the condenser and returned to the mixing chamber under pressure. The idea of delivering water under pressure through a jet nozzle into a closed tank and maintaining the level of water in the tank constant, together with returning air from a condenser and dissipating the pressure thereof so as to cause the jet of water to enter the body of water at a distance substantially constant from its level so as to produce a multiplicity of small bubbles which rise to the surface of the water, is not to be found in the above-described prior art system.
Before this application was prepared for filing in the Patent Office, a patentability search was conducted which brings to light the following patents as those which are believed to come closest to the subject system and are the closest references of which the Applicant is aware:
______________________________________ 3,565,767 Light 957,686 Kalb 3,852,162 Light 957,850 Kalb 3,192,130 Potthorst 2,059,415 Germam ______________________________________
Referring briefly to the disclosures of the more pertinent of the above-listed patents, it is noted that the German patent discloses the idea of forming bubles by introducing a gas into the body of a liquid below the level thereof and which bubbles detoxify spent lyes. It does disclose the production of an initimate mixture of gas and liquid by directing a continuous sharp jet of liquid on the surface of the liquid in a reservoir in such a way that the gas introduced in the vicinity of the jet is disintegrated into bubbles. Thus, it appears that the liquid is introduced into tank 1 by a conduit 10 and additional liquid under pressure is introduced through tube 8 onto the level of the liquid to form the bubbles. In accordance with this patent there is no concept of recycling a mixture of water vapor and gas in a closed circuit including a condenser and returning the gas from the condenser to the tank under moderate velocity which is dissipated by a baffle. Thus, gas appears to come from the pipe 8 but it appears that pressure of such gas would be so great as to disturb the level of the liquid in the tank, and there is certainly no baffle for dissipating such velocity.
In accordance with Light U.S. Pat. No. 3,565,767, a body of water 15 is shown as having an upper surface that is maintained at a constant level by a drainoff. This leaves an evaporating space 16 above the water level. Water is introduced into the evaporator 10 through tube 33 and air is introduced at the inlet 17. Water vapor is drawn off at the outlet 18. In accordance with this patent, there is no mixing chamber in which jets introduce water under pressure into a body of water the level of which is maintained substantially constant to form a multiplicity of bubbles which pass upwardly through the water body to the surface to entrain water in the form of vapor. It is also clearly lacking in any closed circulating system including a condenser from which air is returned to the tank under low pressure which is dissipated by a baffle in the tank.
In accordance with Light U.S. Pat. No. 3,852,162, air and water vapor are fed under pressure to the mingling chamber 10. The water vapor comes from a source 14 of condensible vapor while the gas which is air comes from the source 18. This patent does disclose a circulatory system including a condenser and air from the condenser mixes with air from the source 18 before it is introduced into the mingling chamber; however, this air is clearly under pressure which ordinarily would disturb the surface of the water in the mingling chamber and impair the function of bubbles which might be charged thereinto. This patent is clearly lacking in the concept of introducing recycled air at a velocity which is dissipated by impingement on a baffle.